It is related in the first person by the supposed hero, Caleb Williams.

He represents himself as private secretary to a gentleman of high family named Falkland.

Caleb accidentally discovers that his patron has, in a moment of passion, committed a murder.

Falkland confesses the crime to Caleb, and tells him that henceforth he shall always suspect him, and keep watch over him.

Caleb finds this watchfulness insupportable, and tries to escape, but without success.